This is in CoffeeScript rather than JavaScript, but hopefully it should be clear. In our app we typically have to load multiple things before rendering a page. Using jQuery's Deferred objects the pattern is very simple. This is probably the most basic example we use. I've got some more interesting cases as well, such as fetching many records in …

when.coffee

# With deferred objects
$.when(loadSomething1(), loadSomething2(), loadSomethingElse())
  .done(-> renderPage())
  .fail(-> renderFailure())

# With callbacks, can't operate in parallel, error cases repeated
loadSomething1(
  success: loadSomething2(
    success: loadSomethingElse(
      success: renderPage(),
      error: renderFailure()
    ),
    error: renderFailure()
  ),
  error: renderFailure()
)

For this case, the choice is certainly clear. The DOM Futures examples I saw did not involve multiple async calls, and then success/fail callbacks that fire after the n-number of callbacks fired/completed.

Thanks for the example.